Quick-opening envelope



Sept. 28, 1943. E. B. BERKOWITZ QUICK OPENING ENVELOPE INVENTOR fuyefie 5 fimfow/fz BY ATTRN EY Patented Sept. 28 1943 QUICK-OPENING ENVELOPE Eugene B.

Berkowitz, Kansas City, Mo., asslgnor to Berkowitz Envelope Company, Kansas Ci Mo., a corporation of Delaware Application May 1:1, 1941, Serial No. 393,968

5 Claimj. This invention relates to envelopes particula ly for containing individual quantities. of materials, for example an-individual portionof phyla;

dered chocolate as used at soda fountains, restaurants, and the like, in.the pr'ep ar.ation of a cup of chocolatebeverage.

- Thepresent application isfdirected toan improvementiin the envelope structure disclosed in my copending application Serial No. 251,001,

filed January 14, 1939. In envelopes of" the above entitled application, it is found that the spots of adhesivegpenetrate the fibers of the paper andthe fibers are so firmly adhered that when-thesealing .flap is-pulled loose the'flbers do not break apart cleanly andtend, in some instances, to tear the sealing fiap.

'It is, therefore-a principal .object of the present invention to provide sealing spots of a shape and form that the edges of the non-adherent material which limits the effective sealing area form snear points on which the fibers are severed when the sealing flap is pulled to open position.

In accomplishing this and other objects of the invention, as hereinafter pointed out, I have provided improved structure, the preferred form of which is illustrated in the accompanying drawing, wherein:

Fig. 1 is a perspective view of an envelope constructed in accordance with the present invention and showing the sealing flap in sealed position.

Fig. 2 is a perspective view of the inner side of a blank from which the enevelope is formed, portions of the side flaps being turned back to illustrate the adhesive repellent coating.

Fig. 3 is a perspective view of the blank with the side flaps folded and sealed to each other, but showing the end flaps in extended position.

Fig. 4 is a perspective view of the envelope illustrated in Fig. 1, but showing the method of breaking theseal of one of the end flaps to permit emptying of the contents of the envelope.

Fig. 5 is a perspective view of the envelope showing manipulation thereof in shaping a spout f the pull tab so as to facilitate emptying of the contents into a container.

Referring more in detail to the drawing:

I designates an envelope blank shaped to provide a substantially rectangular body portion 2 definedby lines of fold 3-4 and -6. Extend.- ing laterally from the lines of fold 3 and 4 are a side flaps 1 and 8, the side flap 8 being of greater width than the flap 1 so that when they are folded over the body portion 2 the marginal edge type illustrated in the 9 thereof will overlap a stripe of sealing gum- I ll on the marginal edge of the flap I to form asearn l l offset from the median line'of the envelope, asshown in Fig. 3.

The ends of the body portion 2 areprovided with endfiaps l2 and i3. Y The fiap I2 is of. conventional. shape,-- but the flap 113 has a central. tab-like portion M- projecting therefrom andwhich is provided with a substantially straight lower edge- It extending parallelwith the fold line 5. The tab it may have diverging side edges l6, and i1 merging-into the edges of the end-flap on curves as indicated at [8 and i9. The-.fiap [2' may be provided with gum'ZU extending across-the.width thereof to-seal against.

. .the side flaps I and 8 when the flapis folded on the line of folds.- tab-like portion i i-has a series of gum spots 2! applied on the inner face thereof and whichare adapted toseal against limited sealing areas- 22 on the side flaps l and B when the flap is folded on the line 5. The limited sealing areas 22 are preferably of circular shape and defined within the field of a coating material 23 applied over the area of the side flaps covered by the sealing fiap.

The coating material 23'may consist of ink having an 011 base so that it is repellent to the adhesive spots 2i when the adhesive dries, but provides a sufficient amount of cohesion with the adhesive when the gum is moist to retain the flap in folded position. The circular edges 24 of the coating which define the sealing areas 22 form shear points on which adhering fibers are caused to tear oil? when the flap is opened, as

later described.

The blank forming the envelope may be printed with the adhesive repellent coating material 23 and ,then folded in a conventional envelope forming machine and wherein the gum 2|! is applied to the flap l2, then dried, and the blank delivered to a folding mechanism which folds the side flaps 'I and 8 on the side folds 3 and 4 after the seal gum III has been applied so that the side flaps are connected from the back portion of the completed envelope as shown in Fig.

3. After the blank has been thus folded, the inked portions of the side flaps appear as in Fig. 3 and conform to substantially the shape of the end flap [4. In the next operation, the fiap I4 is provided with the gum or adhesive spots 2| and folded over the coated area of the side flaps on the fold line 5 to bring the gum spots in sealing contact with the areas 22. Attention is dirooted to the fact that the adhesive spots are of Thee-d flap carrying the I folded during the remaining operations on the envelope and until a positive seal is eilected with the limited areas 22.

Upon drying of the adhesive, those portions in contact with the coating 23 crystallize and have no function after the tackiness thereof has been destroyed incidental to drying of the adhesive. 'I'l' erefore, after the adhesive has dried, the closure of the end fiap' i4 is dependent entirely upon the portions of the adhesive adhering to the circular areas 22 wherein the seal is directly between the fiber surface of the flap II and that of the side flaps of the envelope.

The envelope may then filled through the opposite end in a conventional filling machine, after which the gum 20 is moistened and the fiap l2 folded on the line I so that the gum seaiingly engages the side fiaps to retain the contents.

When the envelope is opened, the tab it may be grasped between the thumb and forefinger as shown in Fig. 4, and drawn retractively to break the seal at the spots 22. As above pointed out, the adhesive penetrates the fibers of the paper when it is moist, and when dry firmly engages the fibers oi the paper, so that when the fiap is piulled open, as shown in Fig. 4, the adhered fibers on the flap remain in sealing engagement with the fibers of the sealing spots, but as the fibers are drawn along the curved edges 24 they are severed and break loose so that they do not cause tearing of the flap.

Attention is particularly directed to the fact that the curved shear edges defined by the coating are arranged transversely to the direction of the pull of the fia'p when it is opened so that eachfiber is drawn against a portion of the curved shear edge and therefore each fiber is se ered cleanly and individually. The fibers nearest the ends of the diameter of the sealing areas are first severed, followed by severance of the intermedi-- ate fibers as the fiap is pulled open, until the fibers at the longitudinal diameter are severed. With this arrangement, the fibers are more easily severed and the flap is readily opened.

What I claim and desire to secure by Letters Patent is:

1. A quick opening envelope formed of fibrous material including, a body portion and a seal flap portion extending along an opening in said body portion through which contents of the envelope is adapted to be emptied, a gum repellant coating on one of said portions and contacting the other portion when the seal flap portion is in sealed position, said portion provided with the gum repellent coating having restricted uncoated sealing spaces within said coated area, gum between said portions for eiiecting seals at said restricted spaces, and substantially arcuate cutting edges provided by said coating on sides of the sealing spaces nearest said opening for severing any fibers which are imbedded in said gum when the flap portion is pulled loose in Opening of the envelope.

2. A quick opening envelope formed of fibrous material including, a body portion and a sea fiap portion extending along an opening in said body portion through which contents of the envelope is adapted to be emptied, a gum repellent coating on one of said portions and covered by the other when the flap portion is folded over the body portion, said gum repellent coating having restricted sealing spaces within the area thereof with the edges of said gum repellent coating at said spaces forming arcuate cutting edges, and gum between said portions, said gum repellent coating having a character to effect adhesiveness of the moist gum thereto and to repel adhesiveness of the gum when the gum is dry whereby the gum is effective over the coated area including said restricted sealing spaces when the gum is moist and efiective only at the sealing spaces when the gum is dried with the cutting edges serving to shear any fibers imbedded in said spaces when the flap portion is pulled loose at the sealing spaces upon opening of the envelope.

3. A quick opening envelope formed of fibrous material including, a body portion and a seal fiap portion extending along an opening in said body portion through which contents of the envelope is adapted to be emptied, a gum repellent coating on one of said portions and engaged by the other when the seal fiapportion is closed over the body portion, said portion provided with a coating having circular uncoated sealing spaces within the gum repellent coating, cutting edges formed by the coating at edges of the circular sealing spaces nearest said opening, and gum between said portions for efi'ecting seal of the portions at said spaces, said cutting edges being adapted to sever fibers that are imbedded in the gum of said spaces when the fibers are drawn thereacross upon pulling of the seal flap portion loose at said sealing spaces.

4. A quick opening envelope formed of fibrous material including, a body portion and a seal fiap portion extending along an opening in said body portion through which contents of the envelope is adapted to be emptied, a gum repellent coating on one of said portions and covered by the other when the fiap portion is folded over the body portion, said gum repellent coating having restricted circular sealing spaces within the area thereofwith the edges of said gum repellent coating at said spaces forming arcuate cutting edges, and gum between said portions, said gum repellent coating having a character to effect adhesiveness of the moist gum thereto and to repel adhesiveness of the gum when the gum is dry whereby the gum is efiective over the coated area including said restricted circular sealing spaces when the gum is moist and effective only at the sealing spaces when the gum is dried with the cutting edges serving to shear any fibers imbedded in said spaces when the fiap portion is pulled loose at the sealing spaces upon opening of the envelopes 5. A quick opening envelope formed of fibrous material including, a body portion and a seal flap portion extending along an opening in said body portion through which contents of the envelope is adapted to be emptied, a gum repellent coating on one of said portions and contacting the other portion, gum between said portions and crystallized upon the gum repellent coating. said portion provided with the gum repellent coating having restricted uncoated sealing spaces within said coated area of a shape forming cutting edges of said crystallized gum converging from opposite sides of said areas to a common meeting point in the direction of the opening for severing any fibers which are embedded in the gum of said sealing areas when the flap portion is pulled loose in opening the envelope.

' EUGENE B. BERKOWITZ. 

